TO THE MEMORY OF ANDREI VLADIMIROVICH ROITER

摘要

Andrei Vladimirovich Roiter, a remarkable mathematician and a rarely interesting personality, passed away. Alhough Andrei Vladimirovich has spent most of his life in Kiev, he is justly considered as one of the most outstanding representatives of the Leningrad algebraic school, and his decease is a great loss to all of us.rnA. V. Roiter was one of the favorite students of Dmitrii Konstantinovich Faddeev; his first scientific results belong to the theory of integral representations, the active development of which has begun just at that time (largely due to the initiative of D. K.). Even in his diploma thesis (which he defended in 1960 at the Leningrad State University) he loudly manifested his worth. It has been known for a long time that cyclic groups the order of which is the square of an odd prime integer have only finitely many different indecomposable integral representations; but it was believed that this result failed to hold for the cyclic group of order 4. A. V. Roiter proved that the cyclic group of order 4 has only finitely many indecomposable integral representations as well, and he explicitly produced all 9 such representations.